reimport module every n seconds

[Santiago Caracol]

> > Don't do that.  ;-)  I suggest using exec instead.  However, I would be
> > surprised if import worked faster than, say, JSON (more precisely, I
> > doubt that it's enough faster to warrnat this kludge).
>
> I'm with Aahz.  Don't do that.
>
> I don't know what you're doing, but I suspect an even better solution
> would be to have your program run a "reconfigure" thread which listens
> on a UDP socket and reads a JSON object from it.  Or, at the very least,
> which listens for a signal which kicks it to re-read some JSON from a
> disk file.  This will be more responsive when the data changes quickly
> and more efficient when it changes slowly.  As opposed to just polling
> for changes every 10 seconds.

Somehow I guessed that I would be told not to do it. But it's my
fault. I should have been more explicit. The data is not just data. It
is a large set of Django objects I call "ContentClassifiers" that have
each certain methods that calculate from user input very large regular
expressions. They they have a method "classify" that is applied to
messages and uses the very large regular expressions. To classify a
message I simply apply the classify method of all ContentClassifiers.
There are very many Contentclassifiers.  I compile the
ContentClassifiers, which are Django objects, to pure Python objects
in order to not have to fetch them from the database each time I need
them and in order to be able to compile the large regular expressions
offline. In Django, I generated and compiled each regular expressions
of each ContentClassifier each time I needed it to classify a message.
I didn't find a good way to calculate and compile the regular
expressions once and store them.

I already tested the automatically generated module: Before,
classifying a message took about 10 seconds, now it takes miliseconds.

My only problem is reloading the module: At the time being, I simply
restart the web server manually from time to time in order to load the
freshly compiled module.